


Octummber 2k19 Feat. The UnderRune Kids

by AlfaNumeric



Category: Deltarune (Video Game), Undertale (Video Game)
Genre: Belly Kink, Deltarune as Undertale Timeline, F/F, F/M, Fluff, Gen, Human/Monster Romance, Inflation, Kink Meme, M/M, Multi, Octummber 2k19, Other, Pre-Undertale Pacifist Route, Sibling Incest, Stuffing
Language: English
Status: In-Progress
Published: 2019-10-01
Updated: 2019-10-01
Packaged: 2020-11-09 05:29:06
Rating: Mature
Warnings: Underage
Chapters: 1
Words: 810
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20848277
Author URL: https://archiveofourown.org/users/AlfaNumeric/pseuds/AlfaNumeric
Summary: WELP, THIS DIDN'T GET FINISHED.A set of fills for the Octummber 2k19 meme.Also an excuse for me to write more stuff with Asriel, Frisk, Chara, Ralsei and Kris.Primarily.I may add other characters if I feel like it.We'll see.DLDR.





	Octummber 2k19 Feat. The UnderRune Kids

**Author's Note:**

> Octummber 2k19 comes from this Twitter post: https://twitter.com/Cowiie_/status/1171141412282359809
> 
> Some assumptions this makes:  
\- Deltarune is a timeline of Undertale, sort of a "golden path" where the Human/Monster War never happened.  
\- This is NOT IN THAT TIMELINE, but the characters from Deltarune exist in this one, and in post-game chapters they will be featured.  
\- It's sort of a hybrid meta-timeline where the circumstances are just right for the whole gang to get together.  
\- Just go with it, OK? It's not wholly important.

The small goat's eyes had grown wide at the spread before him, a whole turkey sitting atop a silver plate flanked with mounds of potato, coins of steamed carrot, and decorated with roasted snail escargot in a heavenly display on Toriel's ebony dining table.

Asriel could hardly keep his tongue in his snout as sparkles filled the gaps in his mind's eye, his tail practically vibrating, his body more than eager to consume as much of this preparation as he was able.

Chara eyed him from the seat beside, her estimate of Asriel's constitution dwarfed by the optimism she gathered from her brother's excited stance. Kid was practically about to jump on top of his chair.

Asriel turned his head to Chara. "Humans get to eat like this all the time?" he asked.

"I mean, not all the time," said Chara. "This is just a once-a-year sort of thi--"  
Her words were cut off by a piled plate of Thanksgiving dinner being plopped in front of her and Asriel.

Just as soon as the plates hit the countertop, Asriel started his crusade against the impeccably dense portion. Hardly giving a second thought, he shovelled forkful after forkful of meat and potatoes into his snout, taking only the time necessary to ensure he didn't throw his food all over himself (as that would make Toriel quite upset, you see.)  
Chara could only watch as the plate disappeared before her eyes into Asriel's lithe frame, a dome starting to shape itself inside his baggy sweater.

In what seemed like a few moments, Asriel's plate was empty and his stomach full, the boy slouching back in his chair.  
Toriel looked over to Chara, noticing her still-full plate.  
"Chara, you haven't eaten yet. Are you okay?"

Chara snapped to attention, stifling a blush, meeting Toriel's gaze. "Yeah, I'm fine. Just uh..."  
She sat herself upright, picking a snail off the plate with her fork. "Deciding where to start."  
Toriel smiled, seemingly satisfied. "Alright, hon. Take your time."

"As for you, Asriel..." Toriel looked to the child, whose eyes were still wide with wonder, his paw on top of his stomach. "Would you like seconds?"

Asriel sat up straight, as if the past minutes hadn't happened, and excitedly responded "Yes please!"

Chara rolled her eyes, all too sure where this was going.

\---

And as she predicted, at the end of supper, Asriel had gone way past his limit.  
The two lay in bed, in pajamas that Asriel had to struggle himself into, his buttons straining with his swollen, drum-tight stomach.

He sniffled gently, making small, pitiful whimpering noises as he tried to quell his pain, but an astounding five plates of food refused to let Asriel forget about his gluttony.

Chara faced the other way, trying to get some sleep, but Asriel's predicament left her restless.

Before long, she'd had enough of Asriel's complaints, so she turned around to face the boy and placed her arm around his chest.

Asriel gasped. "Chara... please... be careful," he whispered between tiny sobs.

"It's okay, little brother, I know what I'm doing," cooed Chara.

She pulled herself up against Asriel, wrapping her other arm underneath him and pulling the pained boy into a gentle spoon. With her first arm, she felt her way down to Asriel's stomach, and slowly but deftly undid the outermost button relative to the boy's gravid belly.

Asriel whimpered at the slight changes in pressure the motion induced, but before long, Chara had undone all of Asriel's lower shirt buttons, allowing his overstuffed midsection to hang free.

Then gently, like a feather on snow, Chara lay her alabaster hand to rest on Asriel's stomach fur. The goat let out a breath, blushing at his sister's touch.

"There. Isn't that better?" Chara whispered into Asriel's ear. Asriel nodded in response, now much quieter than he was.

"Just relax. You're trying to push it back, and making the pain worse."  
Asriel nodded again, inhaling deep before relaxing his torso, pushing the arch of his back into Chara's chest.

"Good boy," Chara said, dragging her fingers along Asriel's belly. "Just keep breathing for me."

Altogether, the goat's midsection must have grown several sizes, shaping itself into a ball almost half his own volume, a quarter again his height in radius. Chara couldn't help but be impressed -- the fact that she could help this at all spoke to her underestimation of Asriel.

He looked as if there was a balloon underneath those vertical stripes, not his own hide, and yet from Chara's touch, it was definitely so.  
Chara nuzzled into Asriel's neck fur, continuing to caress his stomach tenderly, exhaling sharply every time it rumbled underneath her touch.

Before long, the both of them had drifted to sleep, Asriel's last thought before he fell to slumber being of Chara, and his gratitude towards his sister's thoughtful, gentle touch.

**Author's Note:**

> Originally posted to Twitter, and reformatted as appropriate.


End file.
